<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        .top {
            width: 100%;
            height: 100px;
            background-color: pink;
        }
        /* 设置左中右 */
        .left {
            width: 200px;
            height: 300px;
            background-color: yellowgreen;
            position: absolute;
            left: 0;
        }
        .center {
            height: 300px;
            /* width: 200px; */
            background-color: blanchedalmond;
        }
        .right {
            width: 200px;
            height: 300px;
            background-color: coral;
            position: absolute;
            right: 0;
        }
    </style>
</head>
<body>
    <div class="top"></div>
    <div class="box">
        <div class="left"></div>
        <div class="right"></div>
        <div class="center"></div>
    </div>
</body>
</html>